Zombie Zen

Zombie Zen Blog

booksandcatslover:


byemitch:

this bird is smarter than I am

I can’t believe it. Does this amazing creature know fluid properties?? This comes directely from Asgard, I am sure. Odin is still searching for him.


Birds are amazingly smart creatures — crows in particular.  There’s a fascinating TED talk by Joshua Klein given back in 2008 where he shows many examples of crows using tools without prior learning.  That’s right: crows don’t just repeat things they’ve seen, they have an ability to reason and understand their environment.  Klein presents some anecdotes of other learned behaviors, but the most fascinating thing is that crows adapt to us.  They use cars and traffic patterns to crack nuts and get food.

And they teach each other.

It’s an eye-opening video.  Nature is awesome.

booksandcatslover:

byemitch:

this bird is smarter than I am

I can’t believe it. Does this amazing creature know fluid properties??
This comes directely from Asgard, I am sure. Odin is still searching for him.

Birds are amazingly smart creatures — crows in particular. There’s a fascinating TED talk by Joshua Klein given back in 2008 where he shows many examples of crows using tools without prior learning. That’s right: crows don’t just repeat things they’ve seen, they have an ability to reason and understand their environment. Klein presents some anecdotes of other learned behaviors, but the most fascinating thing is that crows adapt to us. They use cars and traffic patterns to crack nuts and get food.

And they teach each other.

It’s an eye-opening video. Nature is awesome.

Chromebook Hacking: Developer Mode

Posted

This is the second part in my series about creating a low-cost programming environment with an HP Chromebook 11. See Part 1 of Chromebook Hacking for the overview. This blog post assumes you have some basic knowledge of using a Linux terminal.

Enable Developer Mode

Danger: This will wipe out your entire local storage! Back up everything!

Enabling developer mode on a Chromebook is the blessed way of “rooting” your Chromebook: it gives you root shell access. This comes with the cost of losing parts of ChromeOS that depend on hardware-backed security systems (namely Netflix. Sad days).

Enabling developer mode is reversible (see below), but going in either direction will wipe your Chromebook’s SSD. Please back up your files first.

Instructions are on the Chromium OS website. For the HP Chromebook 11, the short version is: hold Esc+Refresh+Power button and when you see the boot screen, tap Ctrl+D. Follow the prompts and wait for roughly 10 minutes for the operating system to reinstall.

On the boot screen, you need to press Ctrl+D every time you boot to skip the “Danger, you don’t have verified boot” screen, or you can wait for 30 seconds. You can alternatively press the spacebar to perform a factory reset and disable developer mode.

Go through the standard Chrome OS “create an account” process to get to the desktop.

Install Secure Shell and set up Crosh

This step isn’t strictly necessary, but it gives you a very slick terminal interface. If you decide not to do this, you can always open crosh with Ctrl+Alt+T.

Install Secure Shell from the Chrome Web Store. Right-click on the app’s icon in the shelf and choose “Open as Window”. This allows you to use shortcuts like Ctrl+W inside the terminal without Chrome intercepting them. Click the shelf icon to open a new terminal. Create a new profile with a random non-empty user name (I picked foo) and a host of >crosh.

Secure Shell app with user "foo" and host ">crosh"

Harden your install

Open a bash shell by running shell at the crosh prompt. Inside your bash shell, run this command:

chromeos-setdevpasswd

This sets your Chromebook’s UNIX password for the chronos user — the UNIX user used for any logged in Chrome profile. Now that you’ve enabled developer mode, chronos has the ability to run sudo. Since all Chrome profiles use the same UNIX user account, you will want to open chrome://settings/accounts and whitelist the users that can access this machine. Disable Guest browsing and restrict sign-in to yourself.

Chrome settings with guest browsing disabled and sign-in restricted to Ross's account

Finally, you should prevent your Chromebook from booting anything other than ChromeOS by running the following from your bash prompt:

crossystem dev_boot_usb=0 dev_boot_signed_only=1

The first parameter (dev_boot_usb) disables booting from an external USB stick. The second parameter (dev_boot_signed_only) forbids booting to operating systems that are not signed by Google.

Wrapping Up

Now you have a minimal Linux environment with bash and vim. After poking around a bit, you will quickly notice that only Downloads and /usr/local are writable. In the next blog post, I will introduce Crouton: a less restrictive Linux environment for ChromeOS.

Chromebook Hacking

Posted

HP Chromebook 11 showing a command prompt

In my spare time, I’ve been working on Go-SDL2 and Camlistore. I’m usually not sitting in front of my home desktop, so I want to be able to code anywhere. My battle-worn MacBook Pro could do the job, but it’s heavy, bulky, and aging.

To fix this, I bought the HP Chromebook 11. The display is nice, the price is great, and the keyboard is comfortable. It accepts a microUSB charge, so I don’t even have to worry about packing an extra charger. The bummer is development: good luck trying to run anything besides JSFiddle.

For a while, I was using SSH into my desktop to code. Most of the time this works. The problem was me: some days I would forget to turn on my desktop, other days I left it in Windows, and every day I gritted my teeth if I was coding graphics. I fantasized about a machine that booted quickly and had all the programs I needed.

Turns out, the answer was right in front of me: the Chromebook.

Recipe for Success!

  • Buy the Chromebook
  • Enable developer mode
  • Install Secure Shell and set up with Crosh
  • Harden your install
  • Download and run Crouton
  • Install X11 and xmonad
  • Profit!

Total Cost: $279 + half a day’s worth of work.

Over the next few days, I’ll go into more detail on these steps.

A night of fun hacks

Posted

I discovered that some of my code was still living on my old laptop from high school. The laptop hadn’t been booted in about 4 years, so the clock battery had died, causing the filesystem checks to fail (this is Ubuntu 9.10, which cared about these things). I reset the clock manually, boot up the machine, and decide that to be on the safe (but marginally inefficient) side, I’ll copy my entire multi-GB home directory to my more beefy desktop and filter out what I don’t want there.

Sadly, this laptop came before 802.11n and is limited to 54 Mbps. I have an AirPort Express with only one local port, which is connected to my desktop, but I don’t want to disrupt the network setup. I realize I can chain the Ethernet from my old laptop (named metroid) to my new laptop (named roran), which has 802.11n to connect to my desktop (named nasuada).

It's a UNIX system. I know this.

ross@nasuada$ nc -l 8080 > mybackup.tar.bz2
ross@roran$ nc -l 8080 | nc nasuada.local 8080
ross@metroid$ tar -jcf - $HOME | nc roran.local 8080



I love Unix.

Reblog this if you’re older than Google.

Reblogged from rachelomgosh (originally from i-am-the-phantom)

come-come-cardinal:

keepcalmandgosurfing:

geekyninja1:

attend-hogwarts:

grrrbarrowman:

skarosoul:

image

It scares me that there’s only 1000 reblogs.

It scares me that there’s only 3000 reblogs.

how old is google?

google is 13 today

image

Particularly fitting, I feel.

Why Go Does Not Need Generics

Posted

(This developed from a thread with some other Cal Poly students discussing Go.)

One of the frequently asked questions about Go is why are there no generics in the language. It’s a fair point from the perspective of other OOP languages, but idiomatic Go code un-asks the question.

First, it is important to understand how interfaces work in Go. The gist is that interfaces use virtual method lookups, but retain the underlying type, so a conversion back to the original type is still type-safe. An empty interface (interface{}) works as a type-safe equivalent of C’s void*: you can put any type inside of an empty-interface variable, and then you can un-box it later.

The simplest way to define a linked list is through the empty interface: interface{}.

type Node struct {
    Value interface{}
    Next *Node
}

And indeed, this is how the container/list package package works, give or take some complexity. However, my argument is that this is the wrong way to do this. It requires an explicit boxing/un-boxing hit for every access, and this is where (I think) most of the call for generics comes from. There’s a much more idiomatic way to do this. My two case studies here are the sort package and the container/heap package from the standard library.

We start with sort, which defines an interface, sort.Interface:

package sort

func Sort(data Interface)

type Interface interface {
    // Len is the number of elements in the collection.
    Len() int
    // Less returns whether the element with index i should sort
    // before the element with index j.
    Less(i, j int) bool
    // Swap swaps the elements with indexes i and j.
    Swap(i, j int)
}

This may not strike you as a generic container, but that is precisely the point. You can — with a bit of boilerplate — create a type that wraps a typed slice that implements sort.Interface. Thus, the algorithm can work on any type and only works uses indices. This is much cheaper than boxing/unboxing on access.

The second example is container/heap:

package heap

func Init(h Interface)
func Pop(h Interface) interface{}
func Push(h Interface, x interface{})
func Remove(h Interface, i int) interface{}

type Interface interface {
    sort.Interface
    Push(x interface{}) // add x as element Len()
    Pop() interface{}   // remove and return element Len() - 1.
}

Admittedly, there is a bit more boxing/un-boxing going on here, but the idea is still similar. We now have a data structure that requires very few box/unbox operations (two per push/pop). It is important to note that this is still type-safe.

You could implement a binary tree structure similarly:

package tree

func Search(root *Node, val interface{}) *Node

type Node struct {
    Index       int
    Left, Right *Node
}

type Interface interface {
    Len() int
    Less(i, j int) bool
    Push(x interface{})
    Pop() interface{}
}

The Search function would push the val interface and use it for comparisons against the values stored in the tree, then pop it once finished. Admittedly, this isn’t the prettiest interface, but it works in a pinch. It works out to be only one box/un-box round-trip.

As we’ve seen, by “flipping” around the algorithms and separating them from the data structures using interfaces, we can still reap the benefits of generic containers from other languages.

ladyinterrobang:

jonjonlewis:

thegirlwithagrapefruit:

inspirezme:

There has been a lot of hype, good and bad about the Google Glass. What can unanimously be confirmed is that it is a bold effort by Google to change the way we do things. This morning Google released their first practical vision for the long awaited Google Glass. Although there has still been no word on when it will be released for consumer use, They have released a new video (see below) along with new images and information to get our technology teeth into. Google have reached out to the communities of Google+ and Twitter to give die hard enthusiasts a chance to use the Google Glass.

“We’re looking for bold, creative individuals who want to join us and be a part of shaping the future of Glass. We’d love to make everyone an Explorer, but we’re starting off a bit smaller. We’re still in the early stages, and while we can’t promise everything will be perfect, we can promise it will be exciting.”

Google have decided that its time to put on your glasses and enter a new dimension of technology, let us know whether you are excited or skeptical about the Google Glass.

Watch the video on Youtube here.

[Images and Video from Google / View more at Google Glass]

This is crazy.

Well, I know what the only thing I’m asking for this Christmas…

SO COOL

but

how do people already wearing glasses wear them?

I do remember hearing at one point that they had a way of clipping onto prescription glasses.

(standard disclaimer that I don’t know anything, this is based on speculation and is not an official statement from Google yada yada…)

I think noetic would get a kick out of this website, if he hasn’t seen it already.

I think noetic would get a kick out of this website, if he hasn’t seen it already.